/Engine/Source/Runtime/Engine/Classes/Kismet/KismetSystemLibrary.h
Prints a string to the log, and optionally, to the screen If Print To Log is true, it will be visible in the Output Log window. Otherwise it will be logged only as 'Verbose', so it generally won't show up.
static void PrintString ( const [UObject](API\Runtime\CoreUObject\UObject\UObject) * WorldContextObject, const [FString](API\Runtime\Core\Containers\FString) & InString, bool bPrintToScreen, bool bPrintToLog, [FLinearColor](API\Runtime\Core\Math\FLinearColor) TextColor, float Duration, const [FName](API\Runtime\Core\UObject\FName) Key )